NOx emission control system for hydrocarbon fueled power source
US7790127B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 2, 2009 |
| Grant date | Sep 7, 2010 |
| Priority date | — |
| Expiry date | Mar 2, 2029 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/12
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A method of reducing NOx in a lean burn engine exhaust stream from a hydrocarbon burning engine may be first passing the exhaust stream over a thrifted diesel oxidation catalyst that substantially completes the oxidation of carbon monoxide to carbon dioxide and the oxidation of hydrocarbons (HC) to carbon dioxide and water. Next, separate additions of ozone and ammonia or urea may be introduced to the exhaust gas stream upstream of the catalytic reduction reactor at temperatures below 250 degrees Celsius. The additions of ozone and ammonia or urea modify the exhaust gas composition to improve the performance of NOx reduction catalysts in the catalytic reduction reactor. At temperatures above 250 degrees, the ozone addition may be reduced or eliminated, while the ammonia addition can be controlled as a function of the amount of NOx in the exhaust stream and the temperature of the catalytic reduction reactor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.